Add configuration to make shaded JAR

Adds in the Maven Shade plugin in order to create
a shaded (dependencies included) JAR for a given release. We update
the configuration to use a different JAR and artifact ID in order to
not conflict with the plugin-only JAR.

Author: dchenbec

.gitignore

@@ -1 +1,2 @@
 /target/
+/dependency-reduced-pom.xml

pom.xml

@@ -217,6 +217,29 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>3.2.4</version>
+                <configuration>
+                    <shadedArtifactAttached>true</shadedArtifactAttached>
+                    <useDependencyReducedPomInJar>true</useDependencyReducedPomInJar>
+                    <artifactSet>
+                        <!-- Generally, consumers of the shaded JAR
+                             will already have the driver if they want
+                             the plugin -->
+                        <excludes>com.datastax.oss</excludes>
+                    </artifactSet>
+                </configuration>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>